It's been 18 months since Demi Moore and Ashton Kutcherannounced their split after six years of marriage, but their increasingly bitter divorce battle rages on. The latest salvo comes in the form of a $10 million clash over one of the actor's investment funds, reports the New York Post.

"Ashton and Demi are still not divorced, and no settlement has been agreed, even though they have been in negotiations for over a year," relays a source. "Ashton made a lot of money after they married, but he doesn't believe he owes her as much as she is asking for."

The current situation in a nutshell: A few weeks back, Kutcher and his partners -- Madonna's manager Guy Oseary and billionaire Ron Burkle -- revealed that their A-Grade fund for tech start-ups had an estimated value of $100 million, with more to come from outside investors. That got Moore's attention, and now she wants a chunk.

"Ashton set up A-Grade with Oseary and Burkle in 2010, when he and Demi were still together, but he recently told her lawyers the fund had not made substantial money. In fact, he claimed he had only put about $1 million into it," continues the insider. "Now it seems Ashton and Oseary were working towards a private offering based on a valuation of $100 million. Ashton owns 20 percent of the fund, under California law, Demi should be entitled to half of his share -- $10 million."

The fund has invested in everything from Spotify to Fab.com, and Moore's inner circle considers Kutcher's valuation announcement "audacious and narcissistic."

Reps for the former flames have yet to comment on this latest point of contention.

Kutcher's personal wealth has grown exponentially since he married Moore in 2005, both from his tech investments and his highest-paid actor on TV status, courtesy of "Two and a Half Men." Demi, by contrast, has seen her career slow down in recent years, although TMZ says she remains far richer than her ex. Settlement negotiations have reportedly been "hostile."

Kutcher rebounded from the marital meltdown with Mila Kunis, while Moore has dated several younger men. She was most recently linked to a shaggy-bearded Australian pearl diver.